- Additional LMMS_BUILD flag.
- Disallow on plugins -Wl,-no-undefined which triggers undefined references.
- Make sure X11 headers are found.
Lib ossaudio is needed only for OpenBSD
redundant expression removal
simplify condition for detection OS 'kind'
seems the last commit brought an issue on OSx travis test ....
The user might invoke cmake with CFLAGS containing "-m32" or (on OS X) "-arch i386" while on a 64-bit machine to indicate that it should build for 32-bit instead.
Cross compile support for Win32 and Win64 has been unified,
simplified and adapted to the new MinGW64-based build environment.
This finally allows to produce working Win64 binaries.
(cherry picked from commit 51103bb674)
